<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">

      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类：级联下拉列表 -->
      <!-- 一级分类 -->
      <el-form-item label="课程类别">
        <el-select
          v-model="courseInfo.subjectParentId"
          @change="subjectLevelOneChanged"
          placeholder="请选择">
          <el-option
            v-for="subject in subjectNestedList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="请选择">
          <el-option
            v-for="subject in subSubjectList"
            :key="subject.value"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>

      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面-->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduOss/fileOss'"
          class="avatar-uploader">
          <img :src="courseInfo.cover" width="400px" height="500px">
        </el-upload>

      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/>
        元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
import course from '@/api/edu/course'
import teacher from '@/api/edu/teacher'
import subject from '@/api/edu/subject'

import Tinymce from '@/components/Tinymce'

export default {
  components: {Tinymce},
  data() {
    return {
      courseInfo: {
        title: '',
        subjectId: '',
        teacherId: '',
        lessonNum: 0,
        description: '',
        cover: '/static/01.jpg',
        price: 0
      },
      saveBtnDisabled: false, // 保存按钮是否禁用
      teacherList: [],
      subjectNestedList: [],//一级分类列表
      subSubjectList: [],//二级分类列表
      BASE_API: process.env.BASE_API, // 接口API地址,
      courseId: ''
    }
  },

  watch: {
    $route(to, from) {
      console.log('watch $route')
      this.init()
    }
  },

  created() {
    console.log('info created')
    this.init()
  },

  methods: {

    init() {
      // 路由中有值那么就是更新，需要回显
      if (this.$route.params && this.$route.params.id) {
        /*const id = this.$route.params.id
        console.log(id)*/
        this.courseId = this.$route.params.id
        console.log(this.courseId)
        //根据id获取课程基本信息
        this.fetchCourseInfoById(this.courseId)
      } else {
        // 路由没有id 就是添加 todo 这里有bug
        //this.courseInfo = {...this.courseInfo}
        this.courseInfo = {
          title: '',
          subjectId: '',
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: '/static/01.jpg',
          price: 0
        }
        this.initTeacherList()
        // 初始化分类列表
        this.initSubjectList()
      }

    },

    fetchCourseInfoById(id) {
      // 1.获取课程信息
      course.getCourseInfoById(id).then(responseCourse => {
        this.courseInfo = responseCourse.data.item
        // 2.初始化分类列表 ，获取所有分类
        subject.getNestedTreeList().then(responseSubject => {
          this.subjectNestedList = responseSubject.data.items
          for (let i = 0; i < this.subjectNestedList.length; i++) {
            // 比较所有分类信息，如果课程中的一级分类id等于这个一级分类，获取它的二级分类信息
            if (this.subjectNestedList[i].id === this.courseInfo.subjectParentId) {
              // 回显二级分类
              this.subSubjectList = this.subjectNestedList[i].children
            }
          }
        })

        // 获取讲师列表
        this.initTeacherList()
      }).catch((response) => {
        this.$message({
          type: 'error',
          message: response.message
        })
      })
    },

    initTeacherList() {
      teacher.getList().then(response => {
        this.teacherList = response.data.items
      })
    },

    initSubjectList() {
      subject.getNestedTreeList().then(response => {
        this.subjectNestedList = response.data.items
      })
    },
    subjectLevelOneChanged(value) {
      console.log(value)
      for (let i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id === value) {
          this.subSubjectList = this.subjectNestedList[i].children

          // 把二级分类的值清空
          this.courseInfo.subjectId = ''
        }
      }
    },
    // 上传成功
    handleAvatarSuccess(res, file) {
      console.log(res)// 上传响应
      console.log(URL.createObjectURL(file.raw))// base64编码
      this.courseInfo.cover = res.data.url
      this.$message({
        message: res.message,
        type: 'success'
      })
    },

    beforeAvatarUpload(file) {
      /* const isJPG = file.type === 'image/jpeg'*/
      const isLt10M = file.size / 1024 / 1024 / 1024 / 1024 / 1024 / 1024 / 1024 / 1024 / 1024 / 1024 < 10

      /* if (!isJPG) {
         this.$message.error('上传头像图片只能是 JPG 格式!')
       }*/
      if (!isLt10M) {
        this.$message.error('上传头像图片大小不能超过 10MB!')
      }
      /* return isJPG && isLt10M*/
      return isLt10M
    },

    saveOrUpdate() {
      console.log('next')
      this.saveBtnDisabled = true
      if (!this.courseInfo.id) {
        this.saveData()
      } else {
        this.updateData()
      }
    },

    // 保存
    saveData() {
      course.addCourse(this.courseInfo).then(response => {
        this.$message({
          type: 'success',
          message: '保存成功!'
        })
        return response// 将响应结果传递给then
      }).then(response => {
        this.$router.push({path: '/course/chapter/' + response.data.courseId})
      }).catch((response) => {
        this.$message({
          type: 'error',
          message: response.message
        })
      })
    },

    updateData() {
      this.saveBtnDisabled = true
      course.updateCourseInfoById(this.courseInfo).then(response => {
        this.$message({
          type: 'success',
          message: '修改成功!'
        })
        return response// 将响应结果传递给then
      }).then(response => {
        // console.log(response)
        this.$router.push({path: '/course/chapter/' + this.courseId})
      }).catch((response) => {
        // console.log(response)
        this.$message({
          type: 'error',
          message: '保存失败'
        })
      })
    },
  }
}
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>
